CN112729586B - Temperature field test system - Google Patents
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- CN112729586B CN112729586B CN202011596757.3A CN202011596757A CN112729586B CN 112729586 B CN112729586 B CN 112729586B CN 202011596757 A CN202011596757 A CN 202011596757A CN 112729586 B CN112729586 B CN 112729586B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
- G01K7/16—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements
- G01K7/22—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements the element being a non-linear resistance, e.g. thermistor
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Abstract
The embodiment of the invention discloses a temperature field test system, which comprises an atomic clock system, a frequency counter, a high-stability H clock source, a register, a processor, an incubator, a first measurement module, a second measurement module, a third measurement module and a fourth measurement module, wherein: the atomic clock system is arranged in the constant temperature environment of the incubator, the atomic clock system, the frequency counter, the register, the processor and the incubator are communicated, the frequency counter is also communicated with the high-stability H clock source, and the first measuring module, the second measuring module, the third measuring module and the fourth measuring module are respectively communicated with the processor, the incubator and the atomic clock system. The temperature field test system provided by the invention can determine the temperature coefficient of the atomic clock system through the processor, and determine the temperature control capability of the spectrum lamp, the temperature control capability of the cavity bubble system, the magnetic temperature field coefficient of the cavity bubble system and select the optimal working parameter point for the temperature field related equipment through the measurement module.
Description
Technical Field
The invention relates to the technical field of atomic clocks, in particular to a temperature field testing system.
Background
The passive rubidium atomic clock consists of two parts, namely a physical system and an electronic circuit, wherein the physical system comprises a spectrum lamp, an integrated filtering resonance bulb, a microwave cavity, a photocell, a C field, a thermostat, a magnetic screen and the like; the electronic circuit is composed of a basic isolation amplifier, a DDS synthesizer, a frequency doubling mixer and a servo circuit. The physical system is used as an atomic standard frequency output reference, and the electronic circuit and the physical system form a frequency locking loop for locking the output frequency of the VCXO on the atomic standard reference frequency of the physical system.
The performance of the whole atomic clock system influences the use of the atomic clock, so before or during the process of using the atomic clock again, the atomic clock needs to be tested to determine the performance of the atomic clock.
Disclosure of Invention
The embodiment of the invention provides a temperature field test system which can determine the performance of an atomic clock and select an optimal working parameter point for temperature field related equipment.
The invention provides a temperature field test system, which comprises an atomic clock system, a frequency counter, a high-stability H clock source, a register, a processor, an incubator, a first measurement module, a second measurement module, a third measurement module and a fourth measurement module, wherein:
the atomic clock system is arranged in a constant temperature environment of the incubator, the atomic clock system, the frequency counter, the register, the processor and the incubator are communicated, the frequency counter is also communicated with the high-stability H clock source, and the first measuring module, the second measuring module, the third measuring module and the fourth measuring module are respectively communicated with the processor, the incubator and the atomic clock system;
The first measurement module comprises a spectrum lamp, a first temperature control module, a first measurement module, a display module, the incubator and the processor in the atomic clock system, wherein the first temperature control module and the first measurement module are respectively communicated with the spectrum lamp and the processor, and the display module is communicated with the processor;
The second measurement module comprises a cavity bubble system, a second temperature control module, a second measurement module, the incubator and the processor in the atomic clock system, wherein the second temperature control module and the second measurement module are respectively communicated with the cavity bubble system and the processor;
The third measurement module comprises a cavity bubble system, a third temperature control module, a third measurement module, the processor and a weak magnetic probe, wherein the weak magnetic probe is respectively communicated with the cavity bubble system and the processor, and the third temperature control module and the third measurement module are respectively communicated with the cavity bubble system and the processor;
The fourth measurement module comprises a photoelectric signal acquisition module, a program-controlled amplification module, a voltage-controlled conversion module, a VCXO module, a temperature acquisition module, a temperature compensation module and a processor, wherein the photoelectric signal acquisition module, the program-controlled amplification module, the voltage-controlled conversion module, the VCXO module, the temperature acquisition module, the temperature compensation module, the processor and the program-controlled amplification module are sequentially communicated, and the voltage-controlled conversion module is also respectively communicated with the processor and the temperature compensation module.
In some embodiments, a first thermistor is attached to the interior of the incubator, and the first thermistor is used for acquiring actual temperature information of the incubator.
In some embodiments, the first temperature control module includes a wheatstone bridge and a temperature control chip, where the wheatstone bridge, the temperature control chip, the spectrum lamp, the first measurement module, and the processor are sequentially communicated, and the temperature control chip is used for heating or cooling the spectrum lamp.
In some embodiments, the first measuring module is a second thermistor, and the second thermistor is attached to the surface of the spectrum lamp and is used for measuring the actual working temperature of the spectrum lamp.
In some embodiments, the second temperature control module comprises a heating wire disposed on the bubble system.
In some embodiments, the heating wire is disposed on the bubble system in a double-layer twist close-wound manner.
In some embodiments, the cavity bubble system comprises a cavity, a magnetic induction coil, a first magnetic screen layer and a second magnetic screen layer, wherein the cavity, the magnetic induction coil, the first magnetic screen layer and the second magnetic screen layer are sequentially arranged from inside to outside.
In some embodiments, the magnetic induction coil is wound on the cavity in a double-layer coil winding manner.
In some embodiments, the photoelectric signal acquisition module includes two photocells, where the photocells are respectively disposed at two sides of the tail of the cavity bubble system, and are configured to receive the number of photons emitted by the spectrum lamp and irradiated to the surface of the photocell after passing through the cavity bubble system.
In some embodiments, the temperature acquisition module is a third thermistor, and the third thermistor is attached to a surface of the VCXO module and is configured to measure a temperature of an operating environment of the VCXO module.
Compared with the prior art, the invention has the beneficial effects that: according to the temperature field test system provided by the invention, through the test of the temperature field in the atomic clock system, the temperature coefficient of the atomic clock system can be determined through the processor, the temperature control capability of the spectrum lamp can be determined through the first measurement module, the temperature control capability of the cavity bubble system can be determined through the second measurement module, the magnetic temperature field coefficient of the cavity bubble system can be determined through the third measurement system, and the optimal working parameter point can be selected for the temperature field related equipment through the fourth measurement module.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of a temperature field testing system according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a first measurement module according to an embodiment of the present invention;
fig. 3 is a schematic diagram of a first temperature control module and a first measurement module according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of a second measurement module according to an embodiment of the present invention;
Fig. 5 is a schematic diagram of a second temperature control module according to an embodiment of the present invention;
FIG. 6 is a schematic diagram of a specific winding manner of a heating wire according to an embodiment of the present invention;
FIG. 7 is a schematic diagram of a current flow provided by an embodiment of the present invention;
FIG. 8 is a schematic diagram of a third measurement module according to an embodiment of the present invention;
fig. 9 is a winding method of a magnetic induction coil according to an embodiment of the present invention
FIG. 10 is a schematic diagram of a dual-screen magnetic layer structure provided by an embodiment of the present invention;
FIG. 11 is a schematic view of a cavity cover according to an embodiment of the present invention;
FIG. 12 is a diagram of a test of the front and rear of an added magnetic screen according to an embodiment of the present invention;
FIG. 13 is a schematic diagram of a fourth measurement module according to an embodiment of the present invention;
FIG. 14 is a schematic circuit diagram of a programmable amplification module according to an embodiment of the present invention;
FIG. 15 is a schematic circuit diagram of a temperature acquisition module and a temperature compensation module according to an embodiment of the present invention;
Fig. 16 is a schematic diagram of a voltage control conversion module according to an embodiment of the present invention.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to fall within the scope of the invention.
In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more features. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
In the present invention, the term "exemplary" is used to mean "serving as an example, instance, or illustration. Any embodiment described as "exemplary" in this disclosure is not necessarily to be construed as preferred or advantageous over other embodiments. The following description is presented to enable any person skilled in the art to make and use the invention. In the following description, details are set forth for purposes of explanation. It will be apparent to one of ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well-known structures and processes have not been described in detail so as not to obscure the description of the invention with unnecessary detail. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.
In the embodiment of the invention, the processor can adopt the MSP430 model processing of TI company, the A/D can adopt the ADS1110A0IDBVR of TI company, and the D/A can adopt the TLV5623CDR of TI company.
The embodiment of the invention provides a temperature field testing system which comprises an atomic clock system, a frequency counter, a high-stability H clock source, a register, a processor, an incubator, a first measuring module, a second measuring module, a third measuring module and a fourth measuring module. The following will describe in detail.
Referring to fig. 1, fig. 1 is a schematic diagram of a temperature field testing system according to an embodiment of the invention.
As shown in fig. 1, in the embodiment of the present invention, the atomic clock system 10 in the temperature field test system is placed in the constant temperature environment of the incubator 20, the atomic clock system 10, the frequency counter 30, the register 40, the processor 50 and the incubator 20 are in communication, the frequency counter 30 is also in communication with the high steady H clock source 60 (high steady hydrogen clock source), and the first measurement module 70, the second measurement module 80, the third measurement module 90 and the fourth measurement module 100 are in communication with the processor 50, the incubator 20 and the atomic clock system 10, respectively.
In this embodiment, the atomic clock system 10 to be measured is placed in a constant temperature environment, and in the embodiment, a temperature-controllable incubator 20 is specifically selected, and the temperature-controllable accuracy is better than 0/1 0 C, and it should be noted that, in order to further improve the measurement accuracy of the present invention, the higher the temperature-controlling accuracy of the incubator 20, the better, for example, the equipment with the temperature-controlling accuracy better than 0.05 0 C can be further selected.
The frequency signal output by the atomic clock system 10 is directly sent to the measurement end of the frequency counter 30, meanwhile, the high-stability H clock source 60 signal is sent to the clock reference end of the frequency counter 30, the frequency counter 30 starts counting under the control of the processor 50 by the enabling signal, and the measurement result is sent to the register 40 for storage.
The register 40 transfers the measurement data of the frequency counter 30 to the processor 50 for data processing when the processor 50 data access signal is enabled.
The processor 50 enables the frequency counter 30 to start counting on the one hand, and accesses the frequency count data stored in the register 40 on the other hand, and also has a control function of temperature change of the incubator 20 and a temperature measurement result storage function. And finally, calculating and outputting the temperature coefficient of the atomic clock system.
When each module in the whole schematic diagram works normally, the processor 50 sends a temperature change enabling control signal to the incubator 20, for example, the temperature of the incubator is set to t1= 0 C, the temperature control function of the corresponding incubator 20 is started, and the working temperature of the environment in the incubator 20 where the atomic clock system 10 is located is kept within the range of 25 0C±0.10 C. The processor obtains the actual temperature information T1' by accessing a thermistor temperature sensor (first thermistor) attached to the inner surface of the oven 20. After the temperature is constant (this process requires more than 30 minutes for waiting, which is advantageous for improving the measurement accuracy of the present invention, and the specific judgment is determined by the processor accessing the temperature information T1' data), the processor 50 enables the frequency counter 30 to count the frequency of the atomic clock output signal under the high-stability H clock source clock reference, the frequency counter 30 completes N times of sampling, for example, n=100, and transmits each time of measurement data to the register 40, and the processor 50 obtains the data f11, f12, …, f1N of the frequency counting N times of sampling by accessing the register 40, and performs arithmetic average to obtain the frequency average f1 of the atomic clock output signal when t1=25 0 C.
The same principle of operation can be used to obtain the frequency average f2 of the output signal of an atomic clock (atomic clock system) at t2= 0 C. The temperature field coefficient calculation method of the whole machine comprises the following steps:
where f=f2-f 1, f= (f1+f2)/2, t=t2-T1.
It should be noted that:
1. the calculated system temperature coefficient can be positive or negative.
2. In the embodiment, when the variation range of T is selected, the setting may be performed according to the working condition of the actual atomic clock, the actual working environment temperature is 28 0 C, and the variation is 1 0 C, so that the t1=27 0C,T2=290 C of the incubator may be set during implementation, so that a coefficient value closer to the actual system temperature can be obtained, that is, the measurement accuracy is further improved.
A first measurement module:
Referring to fig. 2, fig. 2 is a schematic diagram of a first measurement module provided in the present embodiment, where the first measurement module includes a spectrum lamp 11, a first temperature control module 71, a first measurement module 72, a display module 73, an incubator 20, and a processor 50 in the atomic clock system 10, and the first temperature control module 71 and the first measurement module 72 are respectively communicated with the spectrum lamp 11 and the processor 50, and the display module 73 is communicated with the processor 50.
Specifically, the atomic clock system 10 and the internal spectrum lamp 11 are placed in a constant temperature environment formed by a constant temperature cabinet 20. In the embodiment, a temperature-controllable incubator is specifically selected, the temperature control precision of the incubator is better than 0.1 0 C, and the higher the precision is, the smaller the measurement error of the invention is.
The processor 50 sets the constant temperature operating temperature T of the incubator 20 by command words, and the specific temperature parameter T should be set in consideration of the actual application environment of the atomic clock. A thermistor is attached to the inner surface of the oven 20 to sense the temperature change and to transmit the actual ambient temperature T' to the processor 50.
The first temperature control module 71 performs control of the temperature of the spectroscopic lamp 11 inside the atomic clock system 10, and a specific set temperature t thereof is set by the processor 50.
The first measurement module 72 completes the monitoring of the temperature of the spectroscopic lamp 11 inside the atomic clock system 10 and feeds back the actual temperature t' measurement to the processor 50.
The processor 50 calculates a temperature control factor of the corresponding spectrum lamp 11 according to the actual working environment temperature T 'of the atomic clock system 10 and the actual working temperature T' information of the spectrum lamp 11, and outputs the temperature control factor through the display module 73.
Referring to fig. 3, fig. 3 is a schematic diagram of a first temperature control module 71 and a first measurement module 72 provided in the present embodiment, wherein the first temperature control module 71 includes a wheatstone bridge 711 and a temperature control chip 712, the wheatstone bridge 711, the temperature control chip 712, the spectrum lamp 11, the first measurement module 72 and the processor 50 are sequentially connected, and the temperature control chip 712 is used for heating or cooling the spectrum lamp 11.
Referring to fig. 3, the wheatstone bridge 711 is composed of two symmetrical resistors R and Ro, rk. The selection of the symmetrical resistors R should satisfy the same manufacturer and the same batch, and should ensure that two symmetrical resistors R are as consistent as possible, especially the temperature coefficient, and in addition, R should be close to Ro and Rk resistance values. Ro is a digital potentiometer, and the processor 50 can assign a value to Ro by a command word, the specific resistance value of Ro reflecting the preset operating temperature t of the spectral lamp 11. Rk is a thermistor attached to the surface of the spectrum lamp for measuring the actual operating temperature t' of the spectrum lamp. When ro+.rk, an electromotive force gradient U AB.UAB is formed at the bridge ends A, B, either positive or negative, and when ro=rk, U AB =0.
The temperature control chip 712 is attached to the outer surface of the spectrum lamp 11, so as to heat the spectrum lamp 11, the heating mechanism is determined by U AB, U AB is positive or negative, and the temperature control chip 712 heats or cools until U AB =0, at which time the actual working temperature of the spectrum lamp 11 is already at the Ro value working point set by the processor, at which time rk=ro.
The first measurement module 72 is a thermistor Rz, and the thermistor Rz is attached to the surface of the spectrum lamp 11 to measure the actual working temperature t' of the spectrum lamp 11 and feed back the measurement information to the processor 50.
The processor 50 sets the temperature of the incubator to be operated at t1=25 0 C by a command word, the incubator 20 performs a temperature-constant operation according to the temperature setting control word of the processor 50, and stabilizes the environmental temperature of the atomic clock placed in the incubator 20 within the range t1=25 0C±0.10 C. The resistance of the thermistor attached to the inside of the oven will change with the temperature of the oven, reflecting the actual ambient temperature T1' at which the atomic clock operates, and transmit the measured information to the processor 50.
The processor 50 at this time indirectly sets the operating temperature t1= 0 C of the spectrum lamp 11 by setting the resistance value of the digital potentiometer Ro in the spectrum lamp 11. Under the action of the wheatstone bridge 711, the thermostat chip 712 is enabled once ro+.rk, until the operating temperature of the spectrum lamp 11 is constant at a preset temperature point, at which time the value of the thermistor Rz should be close to Ro, rk, and this measurement information t1' is transferred to the processor 50.
The processor 50 thus records information about the ambient temperature T1 'at which the atomic clock is operating and about the operating temperature T1' of the spectroscopic lamp 11. Similarly, the processor 50 changes the constant temperature environment temperature of the incubator 20 to a range of t2=26 0C±0.10 C by the temperature setting command word, and accordingly obtains the atomic clock operating environment temperature information T2'. However, the operating temperature of the spectrum lamp 11 (i.e., the resistance of Ro) is not changed at this time, and the internal operating temperature t2' of the spectrum lamp 11 is measured. The calculation method of the lamp temperature field coefficient of the invention comprises the following steps:
for example, if the outside working environment temperature of the atomic clock varies by 1 0 C, i.e., T1 '= 0C,T2'=260 C, and the internal working temperature of the spectrum lamp 11 varies by 0.01 0 C, i.e., T1' = 0C,t2'=120.010 C, then the temperature field coefficient of the spectrum lamp 11 is 100, and obviously, the larger the value, the better the temperature field coefficient, which reflects the temperature control capability of the spectrum lamp 11.
And a second measurement module:
Referring to fig. 4, fig. 4 is a schematic diagram of a second measurement module according to an embodiment of the present invention, wherein the second measurement module 80 includes a bubble system 12, a second temperature control module 81, a second measurement module 82, an incubator 20, and a processor 50 in an atomic clock system, and the second temperature control module 81 and the second measurement module 82 are respectively communicated with the bubble system 12 and the processor 50;
In particular, the bubble system 12 belongs to a physical part of the atomic clock, already contained inside the whole atomic clock. The whole atomic clock is placed in a constant temperature system, such as a constant temperature box 20, and the temperature T of the constant temperature box 20 can be set through the outside.
The atomic clock shell is stuck with a thermistor for sensing the working environment temperature T' of the system and transmitting the temperature information to the processor.
The cavity bubble system comprises a heating wire which is used for heating the cavity bubble system. The surface of the cavity bubble system is stuck with a thermistor (a second measuring module) for sensing the specific working temperature t' of the cavity bubble. The processor monitors the working temperature t of the cavity bubble system by setting the working temperature t of the cavity bubble system and obtaining the working temperature t' of the actual cavity bubble system from the thermistor measuring module.
Referring to fig. 5, fig. 5 is a schematic diagram of a second temperature control module 81 according to the present embodiment, and the second temperature control module 81 includes a heating wire 811 and a wheatstone bridge 812. In the figure, at the wheatstone bridge 812, two R are bridge arm reference resistances, and R should be selected to satisfy two requirements: 1. the model numbers, manufacturers and batches of the two R are required to be consistent, especially the temperature coefficients are required to be consistent, so that the consistency of the resistance values of the two R can be ensured when the temperature changes, and the guarantee is provided for further improving the measurement accuracy; 2. the resistance of R should be chosen to be close to Ro, rk.
Ro is a digitally controlled potentiometer that is set by the processor 50 to a specific value that reflects the actual temperature t of the bubble system 12 of the atomic clock. Rk is a thermistor which is attached to the outer wall of the cavity bubble system and is used for sensing the actual working temperature t' of the cavity bubble system. The semiconductor switching transistor is arranged in the heating circuit of the cavity bubble system 12 to play a role of switching, and the conduction or non-conduction of the transistor is determined by the potential difference of U AB to further determine whether the heating circuit of the cavity bubble system 12 works or not. The heating wire 811 is wound on the outer wall of the cavity bubble system 12, and the heating wire 811 is formed by winding an enameled wire, which is worth mentioning: to reduce the magnetic influence of the system, the heater wire 811 is wound in a double-layer twist close-wound manner, wherein the specific winding manner of the heater wire is shown in fig. 6.
Referring to fig. 6, at any point X on the heating wire, it can be seen that two current paths with the same magnitude flow through, and the current flow direction is as shown in fig. 7:
so according to the right hand screw rule of the energized conductor, it can be seen that: where X produces opposing upper magnetic fields and the total magnetic field strength b=0, the effect of the magnetic on the bubble system 12 can be reduced in the manner described above.
When the wheatstone bridge 812 is unbalanced, i.e., rk+.ro, an electromotive force difference U AB <0 will be generated at terminals a, B. Since Rk is a thermistor with negative temperature coefficient (i.e. the higher the temperature is, the smaller the resistance of Rk is), it is known that when Rk > Ro, the actual temperature t' =69 0 C of the cavity system is smaller than the temperature t=70 0 C set by the processor, the wheatstone bridge 812U AB <0, and the semiconductor switching transistor is in the off state, and U A'B' >0 is the whole cavity heating system works normally.
If Rk < Ro indicates that the actual temperature t' =71 0 C of the bubble system 12 is greater than the temperature t= 0 C set by the processor 50, the wheatstone bridge 812U AB >0, and the semiconductor starting triode is in the on state, where U A'B' =0, i.e. the entire bubble heating system stops working. Since the bubble system 12 typically operates at a temperature substantially greater than the ambient temperature, the bubble system 12 will now release heat to the environment, which is equivalent to cooling the bubble system 12. Ultimately, rk=ro, the entire bubble system 12 is in dynamic balance.
The processor 50 sets the temperature of the operating incubator 20 to t1=25 0 C by a command word, the incubator 20 performs a temperature-constant operation according to the temperature setting control word of the processor 50, and stabilizes the environmental temperature of the atomic clock placed in the incubator within the range t1=25 0C±0.10 C. The resistance of the thermistor attached to the inside of the incubator 50 changes with the temperature of the incubator, reflects the actual ambient temperature T1' at which the atomic clock operates, and transmits measurement information to the processor.
The processor 50 then indirectly sets the operating temperature t1= 0 C of the bubble system 12 by setting the resistance of the digital potentiometer Ro in the bubble system 12. Under the action of the wheatstone bridge 812, once ro+.rk, the heating circuit starts to operate until the operating temperature of the bubble system 12 is constant at a preset temperature point, at which the value of the thermistor Rk should be close to Ro, and this measurement information t1' is transferred to the processor 50.
The processor 50 thus records information about the ambient temperature T1 'at which the atomic clock system 10 operates and the operating temperature T1' of the bubble system 12. Similarly, the processor 50 changes the constant temperature environment temperature of the incubator 20 to the range t2=26 0C±0.10 C by the temperature setting command word, and accordingly obtains the operating environment temperature information T2' of the atomic clock system 10. But at this time, the operating temperature of the bubble system 12 (i.e., the resistance of Ro) is not changed, and the internal operating temperature t2' of the bubble system 12 is measured. The method for calculating the temperature field coefficient of the bubble system 12 of the present invention is:
For example, if the outside working environment temperature of the atomic clock system 10 varies by 1 0 C, i.e., T1 '=25 0C,T2'=260 C, and the internal working temperature of the bubble system 12 varies by 0.01 0 C, i.e., T1' =70 0C,t2'=70.050 C, then the temperature field coefficient of the bubble system 12 is 20, and it is obvious that the larger the value, the better the temperature control capability of the bubble system 12 is reflected.
And a third measurement module:
Referring to fig. 8, fig. 8 is a schematic diagram of a third measurement module 90 according to an embodiment of the present invention, wherein the third measurement module 90 includes a bubble system 12, a third temperature control module 91, a third measurement module 92, a processor 50 and a flux weakening probe 93, the flux weakening probe 93 is respectively communicated with the bubble system 12 and the processor 50, and the third temperature control module 91 and the third measurement module 92 are respectively communicated with the bubble system 12 and the processor 50;
the third measurement module 90 performs a measurement of the magnetic temperature field coefficient of the bubble system 12.
The temperature control component (the third temperature control module 91) in the cavity bubble system 12 consists of a thermistor (the third measurement module 92) and a heating wire and is respectively arranged on the cavity cover and the cavity body, and the temperature control component is matched with a temperature control circuit outside the physical system to control the temperature of the resonant cavity. Adopts a proper temperature control mode, and selects metal with high heat conductivity as the processing material of the resonant cavity.
In addition, the influence of the additional magnetic field generated by the temperature control component on the index is considered. The direct current of the heating component is larger (about 200 mA) and the heating current can also change along with the change of the ambient temperature, so that the wiring direction of the thermistor is the cavity axial direction, the heating wire adopts a double-wire and twisted twist mode, and the temperature control component is designed in such a way, so that the longitudinal component of a magnetic field generated by heating current is basically eliminated, and the deterioration of the residual magnetism of the temperature control component on the rubidium frequency standard index is avoided.
The cavity bubble system comprises a TE011 cylindrical cavity, the TE011 cylindrical cavity is an all-metal cavity, end covers in the cavity are made of alloy materials, and the expansion coefficient of the end covers is required to be larger than that of the metal cavity, so that when the ambient temperature around the cylindrical cavity changes, the expansion size of the alloy end covers with larger expansion coefficient is higher than that of the TE011 cylindrical metal cavity, if the ambient temperature rises, the diameter of the metal cavity is elongated, and meanwhile, the alloy end covers are also elongated, and the elongation size is larger than the diameter elongation size of the metal cavity, so that the actual cavity height is shortened instead, and the frequency of the TE011 cylindrical cavity can be kept unchanged.
In order to make the atomic energy level generate splitting and a quantization axis, so that the atomic frequency standard can work normally under the weak magnetic field, a magnetic induction coil is wound outside the cavity of the cavity bubble system 12 to generate a weak magnetic field coaxial with the cavity, and the magnetic induction coil uniformly outputs wires from a wire outlet for better coils, wherein the magnetic induction coil adopts a double-layer coil winding mode, and the winding mode of the magnetic induction coil is shown in fig. 9.
In some embodiments, in order to make the TE011 cylindrical cavity work under constant ambient temperature conditions, the heating wire can be wound around the transverse section of the cavity outside the cavity, and a temperature control loop is formed with the thermistor and the printed board circuit on the cavity cover. The electric lead can generate a magnetic field, so that the temperature control effect can cause the current change of the heating wire, namely the electrified heating wire can generate a changed magnetic field, and the weak magnetic field generated by the magnetic induction coil is influenced on the action of atomic energy level splitting and a quantized shaft, so that a double-wire twist winding mode is adopted for the heating wire so as to offset the magnetic field generated by the electrified current.
In order to prevent the external magnetic field (such as geomagnetism) from affecting the splitting and the quantized axis of the atomic energy level in the TE011 cylindrical cavity, a double-layer alloy magnetic screen structure (a first magnetic screen layer and a second magnetic screen layer as shown in fig. 10) is designed outside the cavity:
As shown in fig. 10, the bubble system 12 includes a cavity 121, a magnetic induction coil 122, a first magnetic shield layer 123, and a second magnetic shield layer 124, and the cavity 121, the magnetic induction coil 122, the first magnetic shield layer 123, and the second magnetic shield layer 124 are sequentially disposed from inside to outside.
The structure of the cavity cover shown in fig. 11 is designed in consideration of the fact that the light of the spectrum lamp 11 needs to be irradiated into the cavity in correspondence with the specific structure of the magnetic treatment.
In practical operation, the influence of the magnetic field on the transition frequency can reach 10 -9 orders of magnitude. The data provided by IGRF (International Geomagnetic REFERENCE FIELD) shows that the magnetic field distribution at the earth's surface is approximately 0.3 gauss in the normal region and 0.5 gauss in some extremum regions. The magnetic fields in different areas are different in size and direction distribution, namely the same position, and the magnetic fields are changed due to the interference of external factors, namely geomagnetic fields sensed by 87 Rb frequency marks are different. For the frequency scale, the addition of the stable C field to the quantized axis is provided, and other magnetic fields are not expected to interfere with the operation of the system, so that magnetic shielding measures must be adopted in the atomic microwave magnetic resonance area to shield the influence of the external unstable stray magnetic field and the changing geomagnetic field on the 0-0 transition frequency. Just as in our system design described above. To accomplish the measurement of magnetic temperature coefficient, we devised the scheme shown in fig. 8:
Referring to fig. 8, a weak magnetic probe 93 detects points a (located outside the second outer magnetic screen layer), A1 (located inside the second outer magnetic screen layer and outside the first inner magnetic screen layer), and A2 (located inside the first outer magnetic screen layer) in the above diagram, respectively, and obtains corresponding magnetic field magnitude test data Y, Y1 and Y2;
the test points of the temperature control and measurement module (namely the third temperature control module 91 and the third measurement module 92) are positioned outside the secondary outer magnetic screen layer, and the change of the environmental temperature is controlled and measured by the processor 50. Changing the ambient temperature from T1 to T2, and measuring the change data Y (1) and Y (2), Y1 (1) and Y1 (2), Y2 (1) and Y2 (2) of Y, Y and Y2, respectively; respectively obtaining the temperature coefficient of the A point of the environmental magnetic field: external magnetic screen A1 point temperature coefficient: /(I) Inner magnetic shield A2 point temperature coefficient: /(I). An outer and inner magnetic shield temperature coefficient factor: x1=q/Q1, x2=q/Q2.
Fig. 12 shows the effect of shielding from geomagnetism after a magnetic screen is applied (test points are respectively positioned at a and A2). For the original data of fig. 12, we can test the same measuring device at the same place, and it can be obtained from the test, that the geomagnetic field is changed, the magnetic field entering the system is greatly reduced after passing through the magnetic screen, and obviously the obtained value of the temperature coefficient factor X2 of the inner magnetic screen is more than ten thousand, and the larger the value is, the better the value is.
A fourth measurement module:
Referring to fig. 13, fig. 13 is a schematic diagram of a fourth measurement module 100 according to an embodiment of the present invention, where the fourth measurement module 100 includes an optical signal acquisition module 101, a program-controlled amplifying module 102, a voltage-controlled transforming module 103, a VCXO module 104, a temperature acquisition module 105, a temperature compensation module 106, and a processor 50, and the optical signal acquisition module 101, the program-controlled amplifying module 102, the voltage-controlled transforming module 103, the VCXO module 104, the temperature acquisition module 105, the temperature compensation module 106, the processor 50, and the program-controlled amplifying module 102 are sequentially connected, and the voltage-controlled transforming module 103 is also respectively connected to the processor 50 and the temperature compensation module 106.
The photoelectric signal collection module 101 includes two photocells, which are respectively disposed at two sides of the tail of the bubble system 12 in the conventional atomic clock technology, and are used for receiving the number of photons emitted by the spectrum lamp 11 and irradiated to the surface of the photocell after passing through the bubble system 12, and forming photo-detection signal photocurrents I1 and I2.
The program-controlled amplifying module 102 is configured to gain-amplify the optical detection signal detected by the optical battery, and the gain multiple of the gain is set by the external processor 50.
The temperature acquisition module 105 is formed by a thermistor attached to the surface of the VCXO voltage controlled crystal oscillator, and is configured to measure the temperature of the operating environment of the VCXO module 104.
The temperature compensation module 106 is configured to convert temperature measurement information of the VCXO module 104 into voltage, and perform negative feedback compensation on output frequency variation caused by temperature variation of the VCXO module 104.
The voltage-controlled conversion module 103 processes the output voltages of the program-controlled amplifying module 102 and the temperature compensating module 106 under the enabling of the external processor 50, so as to obtain a voltage-controlled voltage, and the voltage-controlled voltage acts on the VCXO module 104, so that the frequency of the output signal of the VCXO module 104 is changed.
Referring to fig. 14, fig. 14 is a schematic circuit diagram of a program-controlled amplifying module 102 according to an embodiment of the present invention, as shown in fig. 14, optical detection signals I1 and I2 obtained by a photoelectric signal collecting module 101 are impedance-transformed and then are sent to a differential amplifier circuit consisting of A1, A2 and A3 operational amplifiers for amplification. The program control gain Ao of the whole circuit is adjusted by the resistance change of the digital potentiometer Rk through the central processing unit, and finally, a proper deviation rectifying signal is obtained and is transmitted to the voltage control conversion module. For a specific atomic clock, because the physical system and the parameters of the adopted VCXO model are different, the program control gain Ao in the module needs to be carefully set to find out the parameter value meeting the actual work.
Referring to fig. 15, fig. 15 is a schematic circuit diagram of a temperature acquisition module 105 and a temperature compensation module 106 according to an embodiment of the invention, as shown in fig. 15, wherein two R and R1 are resistors with the same temperature coefficient, and the resistance should be selected to be equal to Rk. The value of R1 here reflects the actual VCXO module 104 operating environment temperature T. Rk is a thermistor attached to the surface of the VCXO module 104 to sense the actual operating environment temperature T of the VCXO. Therefore, when the operating environment temperature T of the VCXO does not change, the bridge in fig. 15 is in balance, and the temperature compensation voltage value supplied to the voltage-controlled conversion module 103 is 0. Once the working environment temperature T of the VCXO module 104 changes, the resistance value of the thermistor Rk becomes smaller (temperature increases) or larger (temperature decreases), and a voltage difference exists between two ends of the bridge, and the voltage difference is amplified by the operational amplifier a and then becomes a temperature compensation voltage to be transmitted to the voltage-controlled conversion module 103. The amplification gain of the whole circuit is regulated by a negative feedback resistor Rw of an operational amplifier, rw is a digital potentiometer, and the central processing unit realizes the function of changing the compensation factor of the circuit by regulating the resistance value of Rw.
Referring to fig. 16, fig. 16 is a schematic diagram of the voltage-controlled conversion module 103 according to the present embodiment, as shown in fig. 16, the correction signal from the program-controlled amplification module 103 and the compensation voltage of the temperature compensation module 106 are respectively sent to the summing circuit 1031, and the two voltage signals are superimposed and sent to the voltage conversion module 1031.
The voltage translation module 1032 is comprised of A/D, D/A, is enabled by the processor 50 to control operation, and maintains a "normally open" state, i.e., A/D, D/A is always in operation. Taking parallel 8-bit A/D, D/A as an example: the 8-bit data bus obtained by the quantum deviation correcting signal through A/D conversion is directly connected to the input bus of the 8-bit D/A, namely the 8-bit A/D sampling directly drives the 8-bit D/A output voltage-controlled voltage to act on the VCXO, so that the frequency of the output signal of the VCXO module 104 is changed. At the same time, the processor 50 will store 8-bit A/D sample data for further servo processing. By the connection mode, the response speed of the whole circuit is improved.
It should be noted that the protection scope of the present invention is not limited to 8-bit data sampling, but also applies to different bit sampling. If 8 bits of A/D and 10 bits of D/A are selected, the 8 bits of A/D total route is directly connected to the lower 8 bits of 10 bits of D/A.
The beneficial effects of the invention are as follows: according to the temperature field test system provided by the invention, through the test of the temperature field in the atomic clock system, the temperature coefficient of the atomic clock system can be determined through the processor, the temperature control capability of the spectrum lamp can be determined through the first measurement module, the temperature control capability of the cavity bubble system can be determined through the second measurement module, the magnetic temperature field coefficient of the cavity bubble system can be determined through the third measurement system, and the optimal working parameter point is selected for the temperature field related equipment through the fourth measurement module, so that the temperature field test system provided by the invention can determine the performance of the atomic clock and select the optimal working parameter point for the temperature field related equipment.
The foregoing has described in detail a temperature field testing system provided by embodiments of the present invention, and specific examples have been set forth herein to illustrate the principles and embodiments of the present invention, the above description of embodiments being only for the purpose of aiding in the understanding of the methods of the present invention and the core ideas thereof; meanwhile, the contents of the present specification should not be construed as limiting the present invention in view of the fact that those skilled in the art can vary in specific embodiments and application scope according to the ideas of the present invention.
Claims (8)
1. The utility model provides a temperature field test system, its characterized in that, temperature field test system includes atomic clock system, frequency counter, high steady H clock source, register, treater, thermostated container, first measurement module, second measurement module, third measurement module and fourth measurement module, wherein:
the atomic clock system is arranged in a constant temperature environment of the incubator, the atomic clock system, the frequency counter, the register, the processor and the incubator are communicated, the frequency counter is also communicated with the high-stability H clock source, and the first measuring module, the second measuring module, the third measuring module and the fourth measuring module are respectively communicated with the processor, the incubator and the atomic clock system;
The first measurement module comprises a spectrum lamp, a first temperature control module, a first measurement module, a display module, the incubator and the processor in the atomic clock system, wherein the first temperature control module and the first measurement module are respectively communicated with the spectrum lamp and the processor, and the display module is communicated with the processor;
The second measurement module comprises a cavity bubble system, a second temperature control module, a second measurement module, the incubator and the processor in the atomic clock system, wherein the second temperature control module and the second measurement module are respectively communicated with the cavity bubble system and the processor;
The third measurement module comprises a cavity bubble system, a third temperature control module, a third measurement module, the processor and a weak magnetic probe, wherein the weak magnetic probe is respectively communicated with the cavity bubble system and the processor, and the third temperature control module and the third measurement module are respectively communicated with the cavity bubble system and the processor;
The fourth measurement module comprises a photoelectric signal acquisition module, a program-controlled amplification module, a voltage-controlled conversion module, a VCXO module, a temperature acquisition module, a temperature compensation module and a processor, wherein the photoelectric signal acquisition module, the program-controlled amplification module, the voltage-controlled conversion module, the VCXO module, the temperature acquisition module, the temperature compensation module, the processor and the program-controlled amplification module are sequentially communicated, and the voltage-controlled conversion module is also respectively communicated with the processor and the temperature compensation module;
The photoelectric signal acquisition module comprises two photoelectric cells, wherein the photoelectric cells are respectively arranged at two sides of the tail part of the cavity bubble system and are used for receiving the photon quantity of light emitted by the spectrum lamp, which irradiates the surface of the photoelectric cells after passing through the cavity bubble system;
The temperature acquisition module is a third thermistor, and the third thermistor is attached to the surface of the VCXO module and is used for measuring the working environment temperature of the VCXO module.
2. The temperature field test system of claim 1, wherein a first thermistor is affixed to the interior of the incubator, the first thermistor being configured to obtain actual temperature information of the incubator.
3. The temperature field test system of claim 1, wherein the first temperature control module comprises a wheatstone bridge and a temperature control chip, the wheatstone bridge, the temperature control chip, the spectrum lamp, the first measurement module and the processor are in communication in sequence, wherein the temperature control chip is used for heating or cooling the spectrum lamp.
4. The system of claim 3, wherein the first measuring module is a second thermistor, and the second thermistor is attached to a surface of the spectrum lamp and is used for measuring an actual operating temperature of the spectrum lamp.
5. The temperature field testing system of claim 1, wherein the second temperature control module comprises a heater wire disposed on the bubble system.
6. The temperature field test system of claim 5, wherein the heater wire is disposed on the bubble system in a double-layer twist close-wound manner.
7. The temperature field test system of claim 1, wherein the bubble system comprises a cavity, a magnetic induction coil, a first magnetic shield layer, and a second magnetic shield layer, the cavity, the magnetic induction coil, the first magnetic shield layer, and the second magnetic shield layer being sequentially disposed from inside to outside.
8. The temperature field testing system of claim 7, wherein the magnetic induction coil is wound around the cavity in a double layer coil winding.
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